Circuit breaker for ignition systems of internal combustion engines



Oct. 30, 1956 A. c. RUSSELL 2,769,044

CIRCUIT BREAKER FOR IGNITION SYSTEMS 0F INTERNAL COMBUSTION ENGINES Filed Sept. 15, 1954 4 INVENTOR.

United States Patent CIRCUIT BREAKER FOR IGNITION SYSTEMS OF INTERNAL COMBUSTION ENGINES Andrew Craig Russell, Shawnee, Okla. Application September 13, 1954, Serial No. 455,613 6 Claims. (Cl. 200-30) This invention relates to the field of internal combustion engines and, more specifically, to improvements in circuit breaker apparatus for the ignition systems thereof. It may be further noted that the present invention involves improvements over the circuit breaker apparatus, or breaker point assembly as such apparatus are commonly called, disclosed in my co-pending application, now Patent #2,729,725, filed concurrently herewith and entitled Breaker Point Assembly for Internal Combustion Engines.

It is an important object of this invention to provide an improved breaker point assembly adapted for use in the distributor mechanism of motor vehicles or other internal combustion engine devices, which provides a greater electrical contact area than has been available in prior constructions. By means of utilizing essentially a plate-against-plate type of breakable contact wherein the plates may be of size and configuration permitting the passage of a maximum amount of electrical current through the assembly when the plates are brought into engagement during the make period of the operating cycle of the assembly, such result is accomplished.

Another important object of this invention is to provide a construction believed to represent essentially the ultimate in simplicity in a breaker point assembly, with resultant advantages by way of decreased manufacturing costs and the like.

Another important object of this invention is to provide such an assembly which is adapted for substitution in the place of conventional breaker point assemblies which may now be in use in existing distributors.

Other important objects of the invention, including certain important details of construction, will be made clear or become apparent as the following description of the invention progresses.

In the accompanying drawing:

Fig. l is a fragmentary view of a distributor mechanism of an internal combustion engine showing the base and cam forming a part of such mechanism and the breaker point assembly of this invention in elevation;

Fig. 2 is a fragmentary, substantially top plan view of the assembly of this invention in place on the base of a distributor mechanism;

Fig. 3 is a cross sectional view taken on line IIIIII of Fig. 2;

Fig. 4 is a fragmentary cross sectional view illustrating a modified embodiment of the invention taken from a position as indicated by line IVIV of Fig. 3;

Fig. 5 is a fragmentary, side elevational view of a modified form of breaker point assembly contemplated by this invention; and 65 Fig. 6 is a fragmentary cross sectional view taken on line VI-VI of Fig. 5.

The first form of breaker point assembly of this invention is generally designated in the accompanying drawing by the numeral 10 and is shown in Figs. 1, 2 and 3. In Fig. l, the numeral 12 generally designates the distributor mechanism of an internal combustion engine,

such mechanism 12 conventionally including a base 14 and a cam 16 rotatable upon a shaft 18 having its axis of rotation substantially perpendicular to the plane of base plate 14.

Assembly 10 includes a unitary bodyof hard but somewhat resilient plastic material such as nylon generally designated by the numeral 28. Body 20 in turn includes a substantially rectilinear block 22 and a cam follower member 24. Assembly 10 also includes a mounting bracket 26 having a number of perforations 28, 30 and 32 therein disposed for cooperation with the conventional fastening means 34, 36 and 38, provided as a part of distributor 12 for retaining a conventional breaker point assembly therein, it being noted that mounting bracket 26 may preferably be of metal or could be of plastic material formed integrally with body 20 as taught in my abovementioned co-pending application. Assuming that the preferred construction of the present invention is followed wherein bracket 26 is formed of metal, however, body 20 may be mounted upon bracket 26 in any suitable fashion as by a number of countersunk screws 40 passing through perforations in bracket 26 into the body 20 by which they are engaged. As so held upon bracket 26 body 2t") will be disposed in substantially the manner indicated in Fig. 1 when bracket 26 is in place and properly adjusted upon base 14 of distributor 12.

Block 22 is provided with an elongated bore 42 passing therethrough, such bore having a portion of reduced diameter 44 at the end thereof remote from cam 16 presenting an inturned shoulder 46 adjacent said end of bore 42. it is also noted that the longitudinal axis of bore 42 is disposed substantially radially to the axis of rotation of shaft 18 and cam 16 of distributor 12. In the preferred construction, bore 42 is circular in cross section.

Cam follower member 24 is elongated and integrally joined with block 22 at one end thereof by a zone of joinder 48 which, because of reduced thickness, is sufiiciently bendable Without breaking to permit swinging of the opposite end of member 24 toward and away from block 22. As will be clear from Fig. 1, member 24 extends from zone 43 in spaced relation to block 22 into intersecting relationship with the longitudinal axis of bore 42. The member 24 is provided with a projection 50 adapted to engage and ride upon cam 16 in such manner that the member 24 is swung about zone of bend 48 as cam 16 is rotated. A surface 52 is provided on member 24 opposite projection 50 and in facing relationship to the adjacent end of bore 42 for purposes hereinafter to be explained.

An elongated rod 54 is reciprocably mounted within bore 42 and includes a portion 56 of reduced diameter journailed in bore portion 44 and presenting an outturned shoulder on rod 54 in facing relationship to the inturned shoulder 46 of bore 42. In accordance with the preferred construction, rod 54 is of circular cross section and of such dimensions as to be freely slidable longitudinally of bore 42 and adapted for rotative movement within bore 42 about the longitudinal axis thereof. It may be noted that rod 54 extends at both ends thereof from the ends of bore 42.

A contact plate 63 of highly conductive material, preferably silver, copper or the like, is mounted upon the face of block 22 opposite member 24 and cam 16. Plate 60 is provided with an opening 62 therein in alignment with bore 42 and of dimensions for clearing the reduced diameter portion 536 of rod 54 without electrical contact therewith. It may also be noted that plate 60 is provided with a substantially fiat surface 64 of considerable area facing away from block 22. Plate 60 is preferably rectangular and of the same major dimensions as the corresponding dimensions of block 22. Plate 60 is preferably mounted upon block 22 by means of a number of screws 66, 68, etc., passing through cooperating perforations in plate 60 and screwed into the body 22. Plate 60 will normally comprise the grounded side of the electrical circuit of the assembly 10 and electrical connection therewith may, accordingly, be effected in divers suitable fashions, the one illustrated being the provision of a lug or the like 7% of conductive material held by a screw 68 and having a conductive lead 72 soldered or otherwise connected therewith.

A contact disc 74 of conductive material is mounted upon the end of rod 54 remote from member 24 and cam 16 by the passage of an end portion 76 of rod 54 through a central perforation 78 of disc 74 and the crimping of a part of rod portion 76 as at 80 to hold disc 74 rigidly in place upon rod 54. Disc 74 is preferably of large area and of a configuration such as to clear the screws 66 and 68 when disc 74 is in engagement with plate 69, the illustrated configuration which is preferred being circular. Disc 74 is provided with a substantially flat surface 82 facing surface 64 of plate 60 and adapted to conductively engage the latter throughout substantially the entire area of both when rod 54 is fully reciprocated in the direction of member 24 and cam 16. A lug 84 of conductive material is held by crimping 80 in contacting engagement with disc 74 and has soldered or otherwise suitably connected therewith a conductive lead 86 which is, in turn, adapted for connection with the hot side of the circuit (not shown) to be broken by the operation of assembly 10.

As above noted, the preferred construction contemplates rotative movement of rod 54 and disc 74 relative to block 22 and plate 60. The degree of such rotative movement may be limited in any suitable fashion as by the action of lead 86 which is preferably of resilient material adapted to withstand continuous flexing as rod 54 is reciprocated in alternate directions. Such opportunity for rotative movement of rod 54 and disc 74 assures uniformness of wear and continuing complementariness of contour of surfaces 64 and 82.

A coil spring 88 is provided within bore 42 in wound around relationship to the decreased diameter portion 56 of rod 54 and has its opposite ends bearing against shoulders 46 and 58 respectively. Spring 88 thus yieldably biases rod 54 in the direction of member 24 toward a position disposing surface 82 in contacting abutment with surface 64 and, by virtue of the abutment of rod 54 against surface 52 of member 24, urges projection 50 of member 24 against cam 16.

The operation of the assembly 10 will thus be clear as involving the swinging of member 24 about zone 48 as projection 50 rides upon cam 16 to thereby cyclically reciprocate rod 54 against the yielding force of spring 88 to move surface 82 of disc 74 out of engagement with surface 64 of plate 6th. The surfaces 64 and 82 returning to their engaged relationship under the influence of spring 88 whenever projection 56 permits swinging of member 24, and therefore reciprocation of rod 54 and disc 74 toward cam 16.

A modified construction is illustrated in Fig. 4 which differs from that described for Figs. 1, 2 and 3 only in that, instead of a bore 42 of circular cross section, a bore 142 of polygonal cross section is provided and, instead of a rod 54 of circular cross section, a rod 154 of polygonal cross section is provided. Such modified construction serves to prevent rotative movement of rod 152 and disc 74 carried thereby relative to block 22 and plate 60 carried by the latter. Such feature might be desirable or necessary in assemblies 16 in which the disc 74 were of other than circular shape and it were desired to prevent engagement of a portion thereof with the fastening screws 66 and 68 or for other reasons obtaining with respect to the desires of the user.

. Referring now to Figs. 5 and 6 there is illustrated another modified form of the invention differing from that above-described in connection with Figs. 1, 2 and 3 only in the respects now to be noted. In this embodiment, block 22 is provided with an elongated, cylindrical bore 242 of uniform diameter throughout and with an elongated, cylindrical rod 254 also of uniform diameter except for portion 276 thereof in which disc 74 is seated and crimped as at 60. Rod 254 is provided with a circumferential groove 290 adjacent the end of rod 254 which engages face 52 of member 24. Contacting lug84, lead 86 and spring 38, as utilized in the embodiment of Figs. 1 to 3 inclusive, are omitted in the modified embodiment of Figs. 5 and 6 and substituted therefor for performing both the functions of providing electrical contact with disc 74 and of yieldably biasing disc 74 toward plate 60 is provided a leaf spring 292 secured to block 22 by any suitable fastening means such as screws 294. Leaf spring 292 is bifurcated at its free end to present a yoke 296 which is received by and confined within groove 29% of rod 254. An electrical connection between lead wire 236 and leaf spring 292 may be accomplished by soldering or the like as at 298. Preferably, the yoke 296 is of such configuration as to tightly engage rod 254 within groove 290, whereby electrical connection from lead wire 286 is established through conductive spring 222 and conductive rod 254 to contact disc 74. The tensioning of leaf spring 292 is such as to yieldably urge rod 254 in the direction of member 24 for the same purposes as hereinbefore described.

It will now be apparent that this invention fully accomplishes its above stated objects and provides a breaker point assembly of uniquely advantageous construction.

The simplicity of the structure utilized markedly decreases the cost of manufacturing this type apparatus. Moreover, the greatly increased contacting areas provided for the electrical portion of the circuit breaker have been found in practice to result in substantial increases in power and savings of fuel in internal combustion engines with which a breaker point assembly made in accordance with this invention is utilized. It will be evident that many minor modifications and changes could be made without departing from the true spirit and intention of this invention. Accordingly, it is desired to be limited only by the scope of the appended claims.

Having thus described the invention, what is claimed I as new and desired to be secured by Letters Patent is:

l. A breaker point assembly for an internal combustion engine having a distributor mechanism including a base and a rotatable cam, said assembly comprising, in combination, a unitary body of insulating material having a main, block-like portion provided with a straight bore therethrough and a cam follower extension portion integrally attached to said main portion and extending from the latter in a direction disposing a part of said extension portion in spaced alignment with one extremity of said bore, there being a zone of reduced dimension on the extension portion adjacent the extremity thereof attached to said main portion, said extension portion being bendable at said zone thereof to render said part swingable toward and away from said one extremity of the bore; means adapted for mounting the body on said base with said main portion in spaced relationship to said cam the axis of the bore substantially radial to the axis of rotation of said cam, the extension portion in engagement with the cam and said part of the extension portion disposed between the cam and said one extremity; a rod reciprocably mounted in said bore and extending beyond both ex tremities of the latter, one extremity of the rod engaging said part of the extension portion opposite the cam; a contact plate of conductive material mounted on said main portion, having an opening therein in alignment with the bore for clearing the other extremity of the rod, and provided with a substantially fiat surface facing away from said main portion; a contact disc of conductive material mounted on said other extremity of the rod, having a substantially fiat surface facing said surface of the plate, and reciprocable with the rod toward and away from a position placing said surfaces in electrically contacting engagement; means yieldably biasing the disc toward said position; and means for making an electrical connection with each of said plate and said disc respectively.

2. In the assembly as set forth in claim 1, wherein said rod is mounted in said bore for rotative movement relative to the block, whereby any Wear occurring on the plate and disc tends to be uniformly distributed.

3. In the assembly as set forth in claim 1, wherein a portion of said bore and a portion of said rod therewithin are of cross-sectional configuration preventing rotation of the rod relative to the block.

4. In the assembly as set forth in claim 1, wherein a portion of said bore adjacent said plate is of decreased diameter presenting an inturned shoulder, said rod is provided with an outturned shoulder spaced from said inturned shoulder in the bore of the block, and said biasing means comprises a coil spring between said shoulder and bearing thereagainst.

References Cited in the file of this patent UNITED STATES PATENTS 2,106,721 Chermendy Feb. 1, 1938 2,384,828 Fuston Sept. 18, 1945 2,464,779 Brownlee ct al Mar. 15, 1949 2,520,237 Cleary Aug. 29, 1950 2,532,000 West Nov. 28, 1950 2,623,131 Chermendy Dec. 23, 1952 2,664,474 Chermendy Dec. 29, 1953 

